What is wrong with me...getting frustrated this month..?

OK so my Hubby and I have been TTC for a year and a half. I am on cycle day 14 today and no ovulation yet. I use opk and I always see the line get a little darker everyday until I get a positive. Well this month I have had nothing but very light lines. I just don't get it. My periods were very irregular then for the last two months they were regular. We have been to a fertility Dr and all test come back fine. My hubby had sperm testing and everything is fine. I am charting BBT this month and it shows no ovulation. I had surgery almost two years ago and had my right tube and ovar removed and ever since then my periods are crazy. I don't know what to do...any suggestions? I also had Hsg and my one tube is open and everything is fine. What in the world is causing this? Any advice would be great thanks!! Also can you get pregnant if you have late ovulation or is it usually an anovulatory month?